Existing methods for nucleic acid amplification and quantitative analysis include real-time polymerase chain reaction (PCR) and real-time reverse-transcription polymerase chain reaction (RT-PCR). Real-time methods are typically based on the detection of an exponential increase of fluorescence intensity and rapid thermal cycling between the dissociation temperature (˜95° C.), annealing temperature (˜50° C.), and synthesis temperature (˜70° C.).
Digital PCR is another method for quantitative analysis of nucleic acids. By dividing a diluted sample into a large number of small-volume reaction compartments, single copies of nucleic acid template can be confined in isolated compartments and amplified by PCR. Only a “yes or no” readout is required, and the number of target molecules in the sample is determined by performing a statistical analysis on the number of “positive” and “negative” wells. This method transfers the exponential amplification profile into a linear, digital format. These digital PCR methods still require thermal cycling and accurate temperature control, both of which may be challenging to ensure in resource-limited field conditions. Accordingly, there is a need in the art for, inter alia, devices and methods for isothermal processes applicable to detection and even quantification of one or more analytes. The value of such devices and methods would be further enhanced if the devices and methods were in at least some embodiments, manually portable.